Answer:
Bacteria Evolution
This process is called Endosymbiosis.
Step-by-step explanation:
Symbiosis is a relationship in which organisms from two separate species live in a close, dependent relationship. Endosymbiosis (note that endo means within) is a specific type of symbiosis where one organism lives inside the other.
This causes bacteria, mitochondria, and chloroplasts to be similar in size. Bacteria also have DNA and ribosomes similar to those of mitochondria and chloroplasts.
Based on this and other evidence, scientists think host cells and bacteria formed endosymbiotic relationships long ago, when individual host cells took in aerobic (oxygen-using) and photosynthetic bacteria but did not destroy them. Through millions of years of evolution, the aerobic bacteria became mitochondria and the photosynthetic bacteria became chloroplasts.